CSIT 58 Chapter 9
We highly value eyewitness testimony as
See or hear what we wish to
Remember aspects of an experience that are
most consistent with our background
What we see or hear is filtered through our
values, attitudes and expectations.
Eyewitnesses to the Sniper?
Even the expectation of a composite sketch—based on accounts from
eyewitnesses to Monday's shooting outside a Fairfax County,
Virginia, Home Depot—came to nothing. "Because of darkness and
distance and perhaps excitement and adrenaline at the time, we are
unable to come up with a composite," said Montgomery County
police Capt. Nancy Demme.
As The Washington Post and other sources noted, the witnesses gave
"vague and inconsistent accounts," disagreeing on virtually all
details other than the sex of the apparent shooter. All the witnesses
agreed they'd seen a man, but some reportedly described a with
"with dark skin, others with olive complexion, of Middle Eastern
appearance or Hispanic"; one apparently said he was "not white, not
black." Such imprecision is mirrored in the descriptions of the killer's
(or killers') vehicle, which has been variously described a white
Chevy Astrovan, a Ford Econoliner, and a white panel truck.
Gillespie, Nick. ―Shooting Blind.‖ Reason Online.” 17 Oct 2002.
http://reason.com/links/links101702.shtml (6 Nov. 2002)
At the age of 39, James Newsome walked out of a maximum-
security prison in Illinois after 15 years of wrongful incarceration.
Newsome was convicted and sentenced to life in prison after
three witnesses identified him as the man who shot and killed a 72-
year-old grocery store owner on the South Side of Chicago, even
though his fingerprints didn’t match those at the scene.
But in 1994, fingerprint technology proved the real perpetrator
was a man on death row.
Newsome was given a settlement of $140,000 by the state, but
he didn’t think that was enough of an apology.
Now he’s suing the police officers and the Chicago Police
Department for millions for gross misconduct.
Sinatra, Amy. ―It’s Him – Or Is It?‖ ABCnews.com.”
y.html (6 Nov. 2002)
The study of a particular individual or event.
Based on observations or interviews
May be very systematic or superficial
Vivid case studies should be viewed as striking
examples rather than as proof.
Evaluating Case Studies
Demonstrates that an outcome is possible. Ask
Is it typical?
Are there counterexamples?
Are there biases in how it’s reported?
Asians are so good at math; there are four of them in my
algebra class and they have the top scores.
Men are terrible cooks-both my brother and my boyfriend
have burned dinners this year.
Through the Looking Glass:
Student Perceptions of Online Learning
I logged on to my computer one Sunday evening to find myself
immediately greeted by an instant message from a 17-year-old
student in one of my courses. The message was simple: "Help!" As
I later learned, the student had encountered difficulty in conducting
Internet research for a class project. She said she felt like Alice in
Wonderland, having fallen through the looking glass. A computer
novice, she was relieved to find me online that night and was able
to finish her assignment.
This is one example of the effect of computers and the Internet on
students' learning experiences. As distance education becomes
more popular, and as traditional courses require more online
assignments, teachers must consider students' perceptions of
online learning. While many professors and teachers embrace this
technology, many students experience confusion and frustration.
By Linda Peters http://ts.mivu.org/default.asp?show=article&id=907
Through the Looking Glass:
Student Perceptions of Online Learning
Linda Peters provides the case of a 17 year old student who felt
frustrated trying to complete an assignment to prove that teachers
must consider students’ perceptions of online learning.
You need to ask: Is this typical? Are there counterexamples?
I have students who take every online course I offer. Some have
taken almost every online course that is available at the college.
They must not feel too frustrated and would make good
Maybe this instructor arranged her class and instructions poorly.
I was also not impressed by this student using the single word
message of Help! As an instructor, that frustrates me. I don’t know
where to start to assist and sometimes I have hundreds of online
students. It is more effective for a student to ask a question like:
―Can you help me understand the Excel formula for step 3?‖
A systematic collection of observations by people
trained to do scientific research.
This kind of evidence CAN BE very dependable,
but the research must use the scientific
Studies show that violent computer games cause
aggressive behavior in children.
A recent report indicates that female college
students are intimidated by computer classes.
Publicly verifiable data
The data must be obtained under conditions
such that other qualified people can make
similar observations and obtain the same
Precision in Language.
The language must be precise and consistent.
In 1986, scientists reported that extremely gifted 12- and
13-year-olds were especially likely to be left-handed
and to suffer from allergies.
They proposed that the kids, while in the womb, had been
overexposed to testosterone, which might have
triggered both the allergies and the intellectual
excellence. But this exotic idea vaporized in the
summer of 1990 when different researchers-Jennifer
Wiley and David Goldstein of Duke University-did a
follow-up study; they found no evidence of a link
between giftedness and left-handedness and allergies
From Diestler, Sherry. Becoming a Critical Thinker p. 144
Scientific Method: Control
Minimizing extraneous factors that might affect
the accuracy and interpretation.
Use multiple observers
Do in a controlled environment like a lab
Hard to apply in studies of the social world and
human behavior. People may behave differently
when they know they’re being watched.
Evaluating Research #1
What is the quality of the source?
Most dependable are journals where the study is
reviewed by a panel of experts, like the Journal of
the American Medical Association.
Has the study been replicated?
Has more than one study shown the same results?
Are conditions in the research artificial?
How similar are the conditions under which the
research study was conducted to the situation the
researcher is generalizing about?
Evaluating Research #2
Is there a reason for someone to have
distorted the research?
Money, position, prestige..
Has the study been selectively chosen?
Are there studies with contradictory results that
were not mentioned?
How far can we generalize, given the research
At a Lecture-Only 12% Listen
Bright-eyed college students in lecture halls aren’t
necessarily listening to the professor, the American
Psychological Association was told yesterday.
If you shot off a gun a sporadic intervals and asked the
students to encode their thoughts and moods at that
moment, you would discover that:
About 20% of the students, men and women, are
pursuing erotic thoughts.
Another 20% are reminiscing about something.
Only 20% are actually paying attention to the lecture.
12% are actively listening.
The others are worrying, daydreaming, thinking about
lunch or-surprise-religion (8%)
This confirmation of the lecturer’s worst fears was
reported by Paul Cameron, 28, an assistant professor
at Wayne State University in Detroit. The annual
convention, which ends Tuesday, includes about
2,000 such reports to 10,000 psychologists in a variety
Cameron’s results were based on a nine-week course in
introductory psychology for 85 college sophomores. A
gun was fired 21 times at random intervals, usually
when Cameron was in the middle of a sentence.
(Diestler, p. 113)
Has the study been replicated? None stated
Are conditions in the research artificial?
Is firing a gun to interrupt lectures normal?
How far can we generalize given the research sample?
A single 9 week introductory course with 85 students
with one particular teacher.
Are there any biases or distortions in the surveys,
questionnaires, ratings, or other measurements?
Unknown, the data collection method was not
The first head-to-head comparison of the nation’s two most popular
medicines for prostate trouble found that one gives significant
relief while the other is virtually useless.
The two medicines, Hytrin and Proscar, are taken by millions of older
men to relieve the symptoms of an enlarged prostate gland.
The study found that Hytrin eases men’s discomfort by about one-
third, while Proscar works no better than dummy sugar pills.
Prostate drugs generally cost $30 to $45 a month.
The study was financed by Merck & Co., which makes Proscar, and
Abbott Laboratories Inc., the maker of Hytrin.
Although both companies approved the study’s design, Merck
discounted its significance as publication approached in today’s
issue of the New England Journal of Medicine.
Dr. Glenn Gormley, a Merck research official, said that in hindsight,
the study was not set up properly to answer the question of which
drug is better.
(Diestler, p. 146 )
Generalizing Based on a Sample
The sample must be:
Large enough to justify the conclusion. Usually
the more events or people observed, the
Possess as much diversity (breadth) as the
types of events about which conclusions are
As random as possible to prevent getting
groups of people that have biased
What’s wrong with this sample?
In Pennsylvania, where liquor can’t be sold on
Sunday, 2,000 people were interviewed at a
beer festival; 96% of those surveyed believed
that the Sunday ban on liquor sale is outdated.
Clearly, Philadelphians (where the festival was
held) disapprove of the law, commonly called
a Blue Law.
Surveys & Questionnaires
The survey has to be answered truthfully.
People often give answers they think they’re
supposed to give.
Questions may be ambiguously worded.
The wording of the question may be biased.
Answers can even vary based on the position
of the question in the survey and how the
survey is presented.
Previous slide answer: Those surveyed were attending a beer festival
Conclusion and Question
Here’s a conclusion based on a survey:
A U.S. congressman sent a questionnaire to his
constituents and received the following results: 92%
were against government-supported child-care centers.
The question that was asked:
Do you believe the federal government should provide
child-care centers to assist parents in rearing their
(Textbook page 135)
Flaws in the Survey
Leading words: to assist parents in rearing their children
What if you substitute: to assist parents who are unable to
find alternative child care while they are working?
Could you generalize these results to all parents in the
Maybe there is a bias to people who return surveys from
Analogies as Evidence
Proving a conclusion about something unfamiliar by
relying on similarity to something more familiar or that is
easier to study.
A researcher may report that when rats are confined to an
overcrowded cage, they exhibit antisocial behavior; a
conclusion is then drawn about humans, comparing
crowded rats to city dwellers. The researcher may imply
that crime is a result of overcrowded conditions.
(Diestler, p. 169)
1. The number of ways the two things being
compared are similar.
2. The relevance of the similarities and the
3. Try to generate your own alternative analogies
to better understand.
End of Chapter 9 Lecture